Impact engraving tool

ABSTRACT

A hand-held, impact engraving device including a flexible sheathed cable which is reciprocated in the sheath by attachment to a rotary eccentric, and a hammer connected to the cable repeatedly strikes a piston which actuates an engraving tool. Shock of the impact of the hammer on the piston is cushioned by a compression spring between the hammer and the anvil.

United States Patent Ray 1 Sept. 9, 1975 [5 IMPACT ENGRAVING TOOL598,45l 9/1925 France 30/362 [76] Inventor: Archie C. Ray, Rt. l, Boxl5,

Powell, y 82435 Primary Exuminer-Al Lawrence Smith [22] Filed: Nov. 151974 A.ssistunt Exuminer-J. T. Zatarga Attorney, Agent, or FirmRichardD. Law [2]] Appl. No.1 523,993

[52] US. Cl 30/362; 30/362 [57] ABSTRACT [51] Int. Cl. B26F 1/34 [58]Field of Search 30/362 A hand-held, impact engraving device including aflew ible sheathed cable which is reciprocated in the sheath [56]Reierences Ci d by attachment to a rotary eccentric, and a hammer UNn-EDSTATES PATENTS connected to the cable repeatedly strikes a piston 24929] 11/1881 Bends 30/162 which aetuates an engraving tool. Shock of theimpact 1, 4/I890 30/1462 of the hammer on the piston is cushioned by acompression spring between the hammer and the anvil. FOREIGN PATENTS ORAPPLICATIONS 5 [2,807 lU/l920 France 30/362 7 Claims, 3 Drawing FiguresIMPACT ENGRAVING TOOL Various types of engraving machines have beenknown, mostly using rotary engraving tools. For some types of engraving,however, the rotary tools have been found to be only partiallysatisfactory. and for some other types of jobs only a percussion type oftool has been found to be satisfactory. Even in todays highly mechanizedarts, many engravcrs still use a mallet and chisel or engraving tool forcertain types of engraving jobs.

A precision hammer was proposed by Warner, US. Pat. No. 2,787,179,proving a manual actuated, spring loaded hammer. Difierent types oftools are stated to be attachable to the unit. Another type ofpercussion machine was developed by Oehlerking, US. Pat. No. 3,440,861for marking items with a pointed marker. This unit integrates apush-pull type electric driver to reciprocate a marking point. Bautrey,US. Pat. No. 1,375,680, describes a reciprocating perforator, mounted ona lever arm which is spring supported. An electric motor and drivemechanism is incorporated in the perforating head. A paper trimmer, US.Pat. No. 953,856, invented by Pierce et al., utilizes a cam actuatedreciprocating needle. In this device a horizontal, internal rotary camtrack causes reciprocation ofa cam follower with no percussion involvedin the reciprocation of the tool.

According to the present invention there is provided a hammer which isreciprocated by means of a reciprocable flexible cable, actuated by anelectric motor rotated eccentric for adjustably striking a piston,through a compression spring. The piston in turn strikes the chuck foran engraver, adjustably reciprocating the engraver. The engraving toolis held in the chuck which is mounted in a small, easily handheld toolmount at the end of the flexible cable providing complete freedom of theengraving tool for engraving jobs.

Included among the objects and advantages of the present invention is toprovide a hand-held percussion engraving device.

Another object of the invention is to provide a handheld percussionengraving device utilizing a flexible cable from an electrical actuatingdevice to reciprocate an impact piston for striking a chuck for anengraving tool.

Still further object of the invention is to provide a small,light-weight hand grip mounted on a flexible cable for free movement ofan engraving tool held in such holder.

Yet another object of the invention is to provide a simple and easilychanged adjusting system for changing the impact of a hammer on anengraving tool.

These and other objects and advantages of the invention may be readilyascertained by referring to the following description and appendeddrawings in which:

FIG. 1 is a generally schematic perspective of an engraving toolaccording to the invention;

FIG. 2 is an enlarged cross-sectional side clevational view of a handgrip of an engraving tool according to the invention; and

FIG. 3 is a cross-sectional, detail view of the drive mechanism of aflexible cable arrangement for the engraver of the invention.

In the device selected for illustration in FIGS. 1 through 3, a framemember is provided for the drive mechanism of the engraver. As shown,the frame is a box type arrangement which may be attached to a workbench, wall, or the like. but it may take other desired forms forholding the elements of the device in their proper orientation. Thedrive of the engraver of the invention includes an electric motor 12having a belt pulley 14 for driving a belt 16. The belt 16 is arrangedto drive a driven pulley 18 mounted on an axle rotatable in a pillowblock or other bearing arrangement 20. The pulley 18 includes a hub 22provided with a series of holes 24a, 24b and the like, each spaced fromthe center of the hub to provide different distances from the center fordriving a crank arm 26 which is arranged to be attached thereto by meansof a pivot pin 28. The belt 16 is shown as a V-belt and the pulleysarranged to support such a V-belt, however various types of belts may beused with accordingly configurated pulleys. The motor 12 is of necessaryhorsepower for driving the unit, and it preferably should be a variablespeed motor which may be controlled by a foot or a hand controlledrheostat, not shown.

The piston rod or crank 26 reeiprocates a crank follower 30 mounted in aguide 32 having a guide slot 34 formed therein. Bolts 36 secure theguide block 32 to the frame and provide means for adjusting the guideblock to the correct line. The follower 30 reciprocates with the end ofcrank 26 and its stroke is variable, depending on the placement of theother end of the crank arm. Also, the slot 34 should be of sufficientlength to permit the follower to move through the maximum stroke causedby the arm mounted in the outermost hole in the hub of the pulley. Thefollower 30 includes a headed pivot pin 31 which rides in the slot 34for maintaining the end of the crank rod 26 in a reciprocal motion. Aflexible cable 40 is secured in the head 30 by means of a set screw 42whereby the cable 40 reciproeates with the head 30 on actuation of theeccentric mechanism. The cable 40 is mounted in a flexible sheath 44which is secured by means of a ferrule 46 and a grommet 48 to anadjusting screw 50. The adjusting screw 50 is mounted in an angle framemember 52 which is mounted on the frame 10.

The tool holder, shown in FIG. 2, includes an outer tube 60 which isarranged to be held in a user's hands, and the opposite end of thesheath 44 is held by means of a ferrule 62 to a hollow double ended nut64 which in turn is secured to an adjustable hollow bolt 66 threaded tothe threads 68 of the tube 60. The adjusting bolt 50 and the adjustingbolt 66 provide means for the adjustment of the length of the flexiblesheath 44. The flexible steel cable 44 passes through the ferrule 62 andthe adjusting screw on its end extends into a piston 70 having a shortbore 72 therein. The open end of the bore 72 is provided with a hollowscrew 74 which prevents the removal of the cable 40 from the bore 72. Ahammer 76 is soldered, welded, or otherwise secured to the end of thecable 44 and it is mounted in the bore 72, and is prevented from exitingthe bore by means of the hollow screw 74. The hammer 76 is arranged toimpinge on a compression spring 78 so a part of the impact of the hammeris taken up by the spring when the hammer reciprocates to strike thepiston 70. The piston 70 reciprocates in the tube 60 and its end 71strikes an anvil 80 secured to the tube by means of a pin 82. A toolholding chuck 84 is threadedly attached to the end of the anvil 80 andit provides an opening 86 for holding generally square tool ends, in themanner of conventional tool holding chucks such as found in ta chucks,brace and bit, and the like.

The steel cable 40 and flexible sheath 44 are of a length sufficient formaneuvering the graver as desired and to drive the reciprocating hammer76 for actuating a graving tool 90 (FIG. 1) which is mounted in thechuck of the hand held tool holder 60. The adjusting screws at the upperand lower ends of the flexible sheath provide adjustment for the desiredtravel of the hammer 76 and subsequent travel of the piston, to vary thecompression of the compression spring 78 inside the piston portion 70.This permits variance of the impact on the graver tool. Lock nuts shouldbe used with each of the adjusting bolts for securing proper setting ofthe adjusting bolts in their respective frame.

The crank arm 26 mounted on the eccentric hole of the hub providesreciprocation of the head 30 and, also. the steel cable 40. Thereciprocation of the steel cable 40 rcciprocates the hammer 76 whichdrives the hammer 76 onto the compression spring inside of the piston70, which in turn drives the piston 70 against the upper end of thechuck. The compression spring 700 prevents the wire from breaking if theadjustment of the wire is not precise and at the smae time permits avery delicate adjustment of the reciprocation to be made. The drivenchuck 84 is arranged to hold different types of graver chisels orcarving chisels which are, of course, driven by the impact of the piston70 set in motion by the compression spring.

The various hollow adjusting screws and bolts are ar ranged to permitfree reciprocating action of the steel cable 40 therein. The reciprocalmovement of the cable is illustrated as being actuated by an eccentriccrank arm 26 mounted on a pulley. however, other types of reciprocatingmechanisms may be used to reciprocate the steel cable 40 in the flexiblesheath, and for its action in the reciprocation of the hammer 76. Thevariable speed motor 12 provides means for controlling the rate ofreciprocation of the crank. The attachment of crank arm to the hub ofthe pulley 18 provides means for controlling the length of movement ofthe hammer 76 and thereby control the impact of the piston 70 on thechuck for holding a graver tool. By adjusting the length of travel ofthe reciprocating hammer 76 and, of course, by changing the type of toolmounted in the chuck, the engraving machine is arranged to engrave alltypes of metal and further provides an excellent carving machine forwood, plastic, and other types of soft carving material. The flexiblecable provides means for free movement of the handle held by the userpermit ting a high degree of movement of the graver tool held in theunit.

I claim:

1. A hand held impact engraving tool comprising a. frame means;

b. an elongated, flexible cable reciproeably mounted in a sheathadjustably secured to said frame means;

c. means including an electric motor for variably reciprocating saidcable in said sheath;

d. housing means mounted on the end of said sheath and arranged to behand held and including a reciprocable graving tool chuck means;

e. piston means reciprocably mounted in said housing means and arrangedto impinge on said chuck means;

f. hammer means secured to the end of said flexible cable and mounted insaid piston means and reciproeable therein; and

g. compression spring means in said piston means positioned to beimpinged on by said hammer means for reciprocating said piston meansagainst said graving tool chuck means.

2. A hand held impact engraving tool according to claim 1 wherein saidmeans for reciprocating said cable includes a rotary eccentric meansrotated by said electric motor.

3. A hand held impact engraving tool according to claim 2 wherein saidrotary eccentric means is variable.

4. A hand held impact engraving tool according to claim 1 wherein saidelectric motor is a variable speed II'lOKul'.

5. A hand held impact engraving tool according to claim 1 wherein saidhousing means is adjustably mounted on said sheath.

6. A hand held impact engraving tool according to claim 1 wherein saidhammer means is welded to said cable and is freely reeiprocable in saidpiston means.

7. A hand held impact engraving tool according to claim 1 wherein saidhousing means is a small cross section tube easily hand held formanipulating.

1. A hand held impact engraving tool comprising a. frame means; b. anelongated, flexible cable reciprocably mounted in a sheath adjustablysecured to said frame means; c. means including an electric motor forvariably reciprocating said cable in said sheath; d. housing meansmounted on the end of said sheath and arranged to be hand held andincluding a reciprocable graving tool chuck means; e. piston meansreciprocably mounted in said housing means and arranged to impinge onsaid chuck means; f. hammer means secured to the end of said flexiblecable and mounted in said piston means and reciprocable therein; and g.compression spring means in said piston means positioned to be impingedon by said hammer means for reciprocating said piston means against saidgraving tool chuck means.
 2. A hand held impact engraving tool accordingto claim 1 wherein said means for reciprocating said cable includes arotary eccentric means rotated by said electric motor.
 3. A hand heldimpact engraving tool according to claim 2 wherein said rotary eccentricmeans is variable.
 4. A hand held impact engraving tool according toclaim 1 wherein said electric motor is a variable speed motor.
 5. A handheld impact engraving tool according to claim 1 wherein said housingmeans is adjustably mounted on said sheath.
 6. A hand held impactengraving tool according to claim 1 wherein said hammer means is weldedto said cable and is freely reciprocable in said piston means.
 7. A handheld impact engraving tool according to claim 1 wherein said housingmeans is a small cross section tube easily hand held for manipulating.